JPH0780384A - Fluid coating device - Google Patents

Abstract

PURPOSE:To improve film quality of a coating film surface by leveling the coating film surface applied onto a surface of an object to be coated by a slot type fluid coating device. CONSTITUTION:A solvent 27 is sprayed in a fog state or a gaseous state by the leveling device 23 arranged in the vicinity of a coating head 5, so that a solvent atmosphere is formed. A thin coating solution 13 being coated so as to be spread on the surface of the object to be coated 4 from a coating head 5 makes the surface flat by coming in contact with the solvent atmosphere at an undried state as it is.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fluid application device.
More specifically, the present invention relates to a technique for forming a coating film having good film quality in a slot type fluid coating device.

[0002]

BACKGROUND ART In the manufacturing process of integrated circuits, liquid crystal color filters, etc., a coating liquid such as photoresist, filter paint, coating paint, etc. is applied to the surface of an object to be coated such as a wafer or glass substrate, and then several microns It is necessary to form a coating film having a uniform thickness. The film thickness accuracy is required to be within ± 5%, for example, but the request is becoming more and more severe.

As a method of forming such an ultrathin coating film, a spin coating method has been generally used conventionally. This method drops the coating liquid on the surface of the object to be coated,
This is a method in which a spinner spins the object to be coated at high speed to spread the coating solution thinly on the object to form a coating film having a constant film thickness determined by the number of revolutions and the like. However,
In this coating method, only a few% of the coating liquid dropped onto the coating target is coated on the surface of the coating target,
The remaining 90% or more of the excess coating liquid is discharged from the object to be coated, and the coating liquid is wasted excessively. Also,
Since the coating liquid also adheres to the side surface of the object to be coated, the coating film peeled off on the side surface of the object to be coated may adhere to the surface of the object to be coated, or the product yield decreases due to the release coating film, Alternatively, a cleaning process after coating is required.

[0004]

Therefore, as a method for improving the utilization efficiency of the coating liquid and significantly reducing the cost of the coating liquid, the applicant of the present invention has proposed a slot type fluid coating device (slot type mucus). Focusing on the spray coating device), we have been promoting its development and practical application. Some of these research results have already been applied for in Japanese Patent Application Nos. 5-154409, 154410 and others. In this slot type fluid coating device, the coating liquid is adjusted to have a constant film thickness by a slot provided in the coating head to flow out from the coating head, and the coating liquid having a constant film thickness is coated on the surface of the coating object. It is a thing. At the same time, the object to be coated is moving at a speed higher than the outflow speed of the fluid with respect to the coating head. When it is applied to the substrate, it is stretched even thinner and a very thin coating film is formed on the surface of the object to be coated. By using such a slot type fluid coating device, a very thin coating film having a uniform film thickness can be obtained, and the utilization efficiency of the coating liquid is dramatically improved.

In the slot type fluid coating device, the coating liquid having a constant film thickness flows out from the slot, but when the coating liquid is applied to the surface of the object to be coated, it is stretched due to the speed difference. . Therefore, depending on the coating liquid, minute irregularities are generated on the surface of the coating film, which may affect the uniformity of the film thickness of the coating film.

The present invention has been made in view of the above technical background, and an object of the present invention is to form on the surface of an object to be coated in the above-mentioned slot type fluid coating apparatus. It is to provide a method for improving the surface condition of a coating film after coating.

[0007]

SUMMARY OF THE INVENTION A fluid coating device according to the present invention has a slot in the coating head for allowing a fluid to flow to a constant thickness and flowing out, and a coating target relative to the coating head with a gap larger than the thickness. In a fluid application device that applies a constant thickness of fluid to the surface of an object to be coated while moving the object, to generate a solvent atmosphere by spraying a solvent toward the surface of the coating film applied to the surface of the object to be coated. Is provided near the coating head.

[0008]

[Function] A leveling device provided in the vicinity of the coating head sprays a solvent on the surface of the undried coating film which has just been coated, and the coating film is placed in a solvent atmosphere to flatten the coating surface. Can be promoted. Therefore, the surface of a very thin coating film applied by the slot type fluid application device can be finished more flat and the uniformity of the coating film is further improved.

[0009]

1 is a schematic configuration diagram showing a slot type fluid application apparatus 1 according to an embodiment of the present invention (the configuration of the apparatus is described in detail in the specification of the above application). 2 is 2
A moving table placed on parallel rails 3 of a book, which travels horizontally along rails 3 at a constant speed by a servomotor (not shown) or the like. Further, the moving table 2 can vacuum-adhere and convey the coating object 4 such as a glass plate on the upper surface, and the coating object 4 vacuum-adsorbed on the moving table 2 is sent in the arrow direction of FIG. Coating head 5
Is passed under.

FIG. 2 is a partially broken exploded perspective view showing the structure of the coating head 5 used in the fluid coating apparatus 1. This coating head 5 is one in which a thin shim 8 having a certain thickness is sandwiched between a pair of applicators 6, 7 and the applicators 6, 7 and shim 8 are integrally fastened with a bolt and a nut (not shown). Therefore, a slot 9 having a thickness equal to the plate thickness of the shim 8 is formed between the applicators 6 and 7 by the notch portion of the shim 8, and the lower end of the slot 9 is opened by the nozzle port 10 on the lower surface of the coating head 5. ing. A fluid reservoir 11 having a hollow shape is provided in one applicator 6 in the width direction, and the fluid reservoir 11 communicates with an upper portion of the slot 9. Then,
When the coating liquid 13 is injected into the coating head 5 through the coating liquid inlet 12 at the central portion, the coating liquid 13 fills and spreads in the fluid reservoir 11, and further flows out from the fluid reservoir 11 to the slot 9 and is fixed at the slot 9. The coating liquid 13 having a thickness is shaped and sent to the outside from the nozzle port 10 protruding to the lower end surface. At the same time, by partially discharging the coating liquid 13 in the fluid reservoir 11 from the coating liquid discharge port 14, the pressure distribution in the fluid reservoir 11 can be adjusted and the film thickness of the coating film 13a can be made more uniform.

As shown in FIG. 1, the coating head 5 is attached to the upper portion of a bridge 16 which is vertically slidably held by a lift holder 15. That is, the bridge 16 is composed of a pair of lifting rods 17 and a coating arm 18, and the lifting rod 17 is held by the lifting holder 15 so as to be slidable up and down, and the coating arm 18 is placed between the upper ends of the pair of lifting rods 17. The application head 5 is horizontally installed and is attached to the application arm 18. The bridge 16 descends downward together with the coating head 5 by its own weight, but since the air cylinders 19 are installed below the elevating rod 17, respectively, the elevating rod 17
The bridge 16 is supported with its lower end abutting the rod 20 of the air cylinder 19. In addition, the air cylinder 19
By projecting the rod 20 of the bridge 16
The coating head 5 can be raised together with the rod 2
By retracting 0, the coating head 5 can be lowered together with the bridge 16. In the standby state,
As described above, the rod 20 of the air cylinder 19 projects and the coating head 5 rises.

Reference numeral 21 is a measuring head installed in front of the coating head 5, and reference numeral 22 is a linear actuator 22 installed below the coating head 5. The coating object 4 placed on the moving table 2 is sent from the front. Then, the plate thickness (surface height) of the coating object 4 is measured by the measuring head 21, and the protrusion amount of the linear actuator 22 is calculated based on the measured value of the plate thickness by the measuring head 21, and only the calculated amount is linear. The actuator 22 projects. When the linear actuator 22 finishes projecting, the rod 20 of the air cylinder 19 retracts and the coating head 5 descends.
The lower surface of the linear actuator 22 stops in contact with the tip of the linear actuator 22, and the coating head 5 and the bridge 16 are supported by the linear actuator 22. In this state, the amount of protrusion of the linear actuator 22 is such that the coating head 5
Is controlled so as to be a height spaced from the surface of the coating object 4 by a constant distance (a distance larger than the film thickness of the coating liquid 13 flowing out from the slot 9: for example, several tens to several hundreds of microns). There is.

When pressure is applied to the coating liquid 13 in the coating head 5 in this state, the coating liquid 13 shaped to have a constant film thickness flows out from the slot 9 of the coating head 5, and as shown in FIG. 4 is applied to the surface. At this time, since the moving speed of the moving table 2 is higher than the outflow speed of the coating liquid 13 flowing out from the coating head 5, the coating liquid 13 flowing out from the coating head 5 is thinly stretched due to a difference in these speeds, and the coating target 13 is applied. The coating film 1 is applied to the surface of the object 4 and is thinner than the gap of the slot 9 on the surface of the object 4 to be applied.
3a is formed.

Behind the coating head 5 is a leveling device 2
3 is provided, and the undried coating film 13a just applied to the surface of the coating object 4 from the leveling device 23.
A solvent 27 such as thinner is sprayed on the surface in the form of mist or gas to form a solvent atmosphere on the surface of the coating film 13a. 1 and 3 show an example of the leveling device 23,
A pipe 24 having a large number of small holes 25 is arranged in the width direction of the moving table 2.
A solvent 27 is supplied from the solvent tank 26 (the solvent 27 is supplied together with a nonflammable carrier gas such as Ar or N _2).
May be supplied). Solvent 2 supplied in the pipe 24
7 passes through the pores 25 of the pipe 24 and spreads around the pipe 24 in the form of mist or gas to create a solvent atmosphere. The surface of the coating liquid 13 just coated on the surface of the coating object 4 is in contact with this solvent atmosphere. The fine irregularities on the surface of the coating film 13a generated when it is thinly stretched flatten (level) due to the viscosity of the coating liquid 13 itself, but the flattening of the coating film 13a can be further promoted by placing it in a solvent atmosphere. As a result, the coating film 13a having a better surface condition can be formed, the uniformity of the film thickness can be improved, and the coating film 13a having a good film quality can be formed.

FIG. 4 is a perspective view showing another example of the leveling device 28 having a different structure, and FIGS. 5 (a) and 5 (b) are explanatory views of its operation. The leveling device 28 has a beam 30 installed between a pair of rotating arms 29,
A V-shaped groove 31 is provided on the lower surface of the beam 30, and one or a plurality of fine holes 32 are provided on the bottom surface of the V-shaped groove 31. The nozzle opening 10 of the coating head 5 is housed in the V groove 31. In this leveling device 28, a base end portion of a rotating arm 29 is rotatably supported by a supporting portion 33, and the leveling device 28 has an angle of about 180 degrees as shown in FIGS. It can be rotated. Further, as shown in FIGS. 5A and 5B, each pore 32 of the leveling device 28 and the closed tank 34 are connected by a flexible tube 35, and a container in which the solvent 27 is stored is stored in the closed tank 34. 36
Has been paid. Then, when air is sent into the closed tank 34, the solvent 27 in the container 36 is sent to the leveling device 28, and the mist or gaseous solvent 2 is discharged from the pores 32.
7 is blown out.

FIGS. 5A and 5B show the leveling device 2 described above.
8A and 8B are views for explaining the operation of FIG. 8, wherein FIG. 5A shows a state during coating by the coating head 5, and FIG. 5B shows during standby of the coating head 5. At the time of coating by the coating head 5, the V groove 31 and the fine hole 32 of the leveling device 28.
Is facing down. In this state, since the gaseous solvent 27 is blown downward from the pores 32 facing downward, when the coating object 4 just coated with the coating liquid 13 passes below the leveling device 28, The surface of the coating liquid 13 is placed in a solvent atmosphere, the leveling of the coating film 13a becomes good, and a uniform coating film 13a can be obtained.

When the coating head 5 is on standby,
As shown in FIG. 5B, the lower surface of the coating head 5 is covered with a leveling device 28 which is inverted by 180 degrees, and the nozzle port 10 is housed in the V groove 31. At this time, since the nozzle opening 10 is moistened in the V groove 31 by the solvent 27 flowing out from the pores 32, the drying of the nozzle opening 10 is prevented. Therefore, it is possible to prevent the coating liquid 13 from drying or hardening at the nozzle openings 10 of the coating head 5.

[0018]

According to the present invention, the undried coating film just coated by the coating head can be placed in a solvent atmosphere, so that the surface of the coating film can be flattened. Therefore, the surface of the applied very thin coating film can be finished more flatly, the uniformity of the coating film can be further improved, and the performance of the slot type fluid coating device can be further improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a fluid application device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway exploded perspective view showing the coating head of the same.

FIG. 3 is an operation explanatory view of the above leveling device.

FIG. 4 is a perspective view showing another leveling device according to the present invention.

5 (a) and (b) are explanatory views of the operation of the leveling device of the above.

[Explanation of symbols]

 4 coating object 5 coating head 9 slot 13 coating liquid 23,28 leveling device 24 pipe 25 fine hole 30 beam 32 fine hole

Claims (1)

[Claims] 1. A slot in the coating head causes a fluid to flow out with a constant thickness, and the fluid is fixed on the surface of the coating object while moving the coating object relative to the coating head with a gap larger than the thickness. In a fluid coating device that coats a thick fluid, a leveling device for spraying the solvent toward the surface of the coating film applied to the surface of the coating object to create a solvent atmosphere was provided near the coating head. A fluid application device.